Risk of solid cancer increased after bone marrow transplantation

Last Modified: November 1, 2001

Last Updated: 2001-01-31 13:00:35 EST (Reuters Health) - Patients who have undergone bone marrow transplantation for hematologic malignancies face a higher risk of developing subsequent solid cancers, according to a report in the January 15th issue of the Journal of Clinical Oncology.

Second neoplasms occur at an increased rate after chemotherapy and irradiation, the authors note, but whether the regimens employed in association with bone marrow transplantation (BMT) contribute to the formation of subsequent solid cancers is uncertain.

Dr. Smita Bhatia and colleagues from City of Hope National Medical Center, Duarte, California, evaluated the role of pretransplantation therapeutic exposures and transplant conditioning regimens in the development of subsequent nonhematopoietic malignancies in 2129 patients who had undergone BMT.

Twenty-nine patients developed invasive solid tumors during the years after BMT, a rate more than double that expected in the general population, the authors report. By 5 years posttransplant, 1.6% of patients had developed second tumors, and by 10 years posttransplant, the cumulative incidence had reached 6.1%.

New malignancies were much more common after allogeneic BMT (6.4% at 10 years) than after autologous BMT (1.6% at 10 years), the report indicates, and patients younger than 34 years were 5.3 times more likely than the general population to develop solid malignancies.

Compared with the general population, BMT patients faced a 13-fold increased risk of cervical cancer or thyroid cancer, a 27.7-fold higher risk of liver cancer, and a 53.3-fold increased risk of cancer of the oral cavity. Patients who had received total body irradiation tended to develop more secondary liver, thyroid, and oral cavity cancers than did patients who did not receive TBI, the results indicated.

In contrast, the treatments surrounding the BMT, the presence of acute or chronic graft-versus-host disease, and various demographic variables showed no association with the development of subsequent solid cancers. "The contribution of treatment received before or during transplantation remains unclear," the authors conclude.

In comments to Reuters Health, Dr. Bhatia said "it is absolutely imperative that all patients receiving BMT (irrespective of the type of conditioning) be followed long term (for life) for second malignancies and other late effects."

Dr. Bhatia acknowledged, "The number of patients with second cancers was small; hence, the power might not have been adequate to detect the effect of pretransplant chemotherapy."